Zhu Jingyi, Mathes Tilo, Stahl Andreas D, Kennis John T M, Groot Marie Louise
Department of Physics and Astronomy, Faculty of Sciences, Vrije Universiteit, Amsterdam, The Netherlands.
Opt Express. 2012 May 7;20(10):10562-71. doi: 10.1364/OE.20.010562.
Broadband femtosecond mid-infrared pulses can be converted into the visible spectral region by chirped pulse upconversion. We report here the upconversion of pump probe transient signals in the frequency region below 1800cm(-1), using the nonlinear optical crystal AgGaGeS4, realizing an important expansion of the application range of this method. Experiments were demonstrated with a slab of GaAs, in which the upconverted signals cover a window of 120cm(-1), with 1.5cm(-1) resolution. In experiments on the BLUF photoreceptor Slr1694, signals below 1 milliOD were well resolved after baseline correction. Possibilities for further optimization of the method are discussed. We conclude that this method is an attractive alternative for the traditional MCT arrays used in most mid-infrared pump probe experiments.
宽带飞秒中红外脉冲可以通过啁啾脉冲上转换转换到可见光谱区域。我们在此报告使用非线性光学晶体AgGaGeS4对低于1800cm(-1)频率区域的泵浦探测瞬态信号进行上转换，实现了该方法应用范围的重要扩展。用一块砷化镓进行了实验，其中上转换信号覆盖了120cm(-1)的窗口，分辨率为1.5cm(-1)。在对蓝光感光蛋白Slr1694的实验中，经过基线校正后，低于1毫光密度的信号得到了很好的分辨。讨论了进一步优化该方法的可能性。我们得出结论，该方法是大多数中红外泵浦探测实验中使用的传统碲镉汞探测器阵列的一种有吸引力的替代方案。
